Internet access on-board buses, trains, and ferries is becoming increasingly common. As a measure of the need for mobile vehicular Internet access, public transportation agencies in over twenty cities in the USA currently provide such access to boost ridership and many more are planning to incorporate such services. Corporations also provide such access on the commute vehicles for their employees. For instance, in the San Francisco area in the United States, more than one-quarter of a large technology company's work force uses such Internet connected buses. By all accounts, riders greatly value this connectivity. It enables them to browse the Web, exchange email, and work on the way to their destinations.
Despite their increasing popularity, current practices are insufficient and the networks are not optimally engineered. Most current systems use only one wireless uplink for communication. But his provides poor performance because wireless links in vehicular environments tend to be lossy and have highly variable delay. Some systems operate to bond multiple links or paths into a single higher-performance communication channel. These systems stripe data between end hosts across arbitrary paths by using TCP or a protocol inspired by it along each path. This provides automatic loss recovery. These mechanisms work well in an end-to-end setting but not in an in-network proxy setup because loss recovery in them is based on end-to-end feedback. If applied to an in-network proxy system, such an approach would be less than acceptable in hiding losses from users' TCP because of the high delay of paths between two cooperating proxies.
Other current practices, combine multiple wide-area wireless links to improve Internet connectivity on vehicles. For example MAR uses a simple connection-level striping policy but leaves open the task of building more sophisticated algorithms. Comparatively, Horde specifies a QoS API and stripes data as per policy. It requires that applications be rewritten to use the API which is limiting and arduous. Also, current practices such as MAR and Horde do not focus on loss recovery as a key variable to be addressed when wirelessly communicating data.
Delay-based path selection across wireless links is addressed by current practices. However, current solutions are lacking since it does not consider the impact of loss. Several current solutions focus on the case where the wired links behind the base-stations are the bottlenecks and focus on aggregating their bandwidths. Further, prior work includes studies of TCP's performance over wireless links. Both network-level and host-level improvements have been proposed.
Currently deployed erasure codes and other forward error correction (FEC) techniques guard against packet losses. Such techniques, however, do not focus on partial recovery. Systems such as MORE and COPE use network coding in multi-hop wireless mesh networks. These systems exploit the broadcast nature of wireless medium and code across multiple nodes and tend to contribute to signal/data loss.
From the foregoing it is appreciated that there exists a need for systems and methods to ameliorate the shortcomings of existing practices.